1. Field of the Invention
This invention relates to an economical coating composition for porous substrates that provides extremely glossy surfaces, is capable of supporting holographic images, provides good oxygen barrier properties as well as good oil, grease, solvent and water resistance. Said coatings on paper substrates are printable, biodegradable, recyclable, and repulpable. They are also suitable for use in conjunction with food products. This invention also relates to a process for applying said coatings onto porous substrates as well as a process for the economical production of inexpensive holographic images on substrates such as paper and cardboard containers.
2. Prior Art
It has been desirable to produce holographic or 3-dimensional graphical images and high gloss paper and high gloss white paper substrates on packaging, marketing, and promotional materials more economically than by manufacturing processes that are currently available. These holographic or 3-dimensional graphical images provide multiple color (rainbow) like affects on the these packaging, promotional, and marketing materials. The high gloss paper and high gloss white paper affects enhance the surface appearance of an otherwise unattractive substrate. These affects appeal to consumers and enhance the products or promotional image. Economics of the current process has deterred many in the highly competitive markets not to include or utilize holographic affects in their marketing or promotional packages. High gloss paper and high gloss white paper substrates are also not economically attractive.
To achieve the holographic image or 3-dimensional graphical images, a holographic pattern or design is selected is then embossed onto the surface of a cylinder or plate. Laser etching has also been introduced into the market. The roller or plate then is used to emboss or impress the holographic image of the roller or plate onto a high gloss smooth surface such as polyester, polyvinyl chloride, polypropylene, polystyrene or polyethylene. Or the holographic image is impressed into a semi-soft or hard coating which was coated onto the polyester. This non aqueous based coating is typically 100% polyurethane. This embossed coating can be transferred with the holographic image or bonded permanently to the carrier depended upon which side of printing was preferred to enhance the holographic image. These embossed holographic image surfaces can be and are typically put through a Vacuum Metal Deposition process, where a certain amount of aluminum is vaporized and redeposited as a solid onto the embossed holographic surface. Highly reflective or dark inks are also utilized to reflect the light to achieve similar effects. This light reflection or mirror image behind the embossed holographic surface then gives a highly glossy attractive 3-dimensional graphical image or holographic image. The mirror surface behind the embossed surface reflects light that provides the holographic effect. This metallizing process is fast and cost effective. This embossed highly glossy smooth holographic 3-dimensional metallized surface is usually then laminated to various papers or itself and other materials and or formed into packages for the consumer to enhance product appeal. The cost of the polyolefins and transfer embossed urethanes as part of the process to deliver the finished holographic 3-dimensional process is very costly and environmentally detrimental. To achieve similar high gloss paper substrates with good barrier properties compared to the embodiments of this invention, typically paper mills and or paper converters laminate polymer films such as, but not limited to, polyester, polypropylene, or polyethylene to various paper substrates. Another process to achieve barrier properties and high gloss is to extrude polyethylene and/or polyethylene teraphthalate onto paper surfaces. Both the laminate materials and extrusion materials are not biodegradable, recyclable, or repulpable. The high costs of the extruded and laminated polymer films and the non-reclamation of the scrap materials make these products economically unattractive for the majority of packaging and promotional materials.
To achieve similar high gloss white paper substrates with good barrier properties compared to the embodiments of this invention, typically paper mills and or converters laminate polymer films such as, but not limited to polyester, polypropylene, or polyethylene to various white (bleached or clay/titanium dioxide coated) paper substrates. Another process to achieve barrier properties and high gloss is to extrude polyethylene and or polyethylene teraphthalate onto white (bleached or clay/titanium dioxide coated) paper substrates. Both the laminate materials and extrusion materials are not biodegradable, recyclable, or repulpable. The high costs of the conventionally fabricated films and non-reclamation of the scrap materials also makes these products also economically unattractive for the majority of standard packaging or promotional materials.
It is therefore desirable to produce a more cost effective way of manufacturing a high gloss, smooth, clear and more environmentally acceptable holographic 3-dimensional metallized products, high gloss papers, and high gloss white paper substrates suitable for use in consumer packaging. Furthermore, it is desirable to produce a holographic 3-dimensional metallized product, a high gloss paper, and a high gloss white paper substrate that can be biodegradable, recyclable and repulpable in current reclamation systems that exists today. The current holographic 3-dimensional metallized extruded and laminated polyolefins, polyesters and urethanes are not recyclable, repulpable, or biodegradable in their usual forms.